1. Field of the Invention
This invention relates to homogeneous compositions comprising a carrier, a microbiocidal compound, and a solvent for the microbiocidal compound which is also compatible with the carrier.
The present invention further relates to a process for imparting microbiocidal properties to polymer compositions comprising adding to the polymer composition a homogeneous microbiocidal composition comprising a carrier, a microbiocidal compound, and a solvent for the microbiocidal compound.
This invention further relates to compositions comprising a homogeneous solution of a liquid plasticizer for vinyl resins, a biologically effective amount of a microbiocidal compound, and a solvent for the microbiocidal compound.
This invention further relates to polymer. e.g.. vinyl resin, compositions comprising an admixture of a polymer and a composition containing a carrier, e.g., plasticizer, and in an amount sufficient to impart microbiocidal properties to the polymer composition, a microbiocidal compound dissolved in a solvent.
2. Prior Art
It is presently common practice to protect polymer or plastic compositions from microbiological, e.g.. bacterial or fungal attack by incorporating microbiocidal compounds into the polymer or plastic compositions. The resulting polymer compositions prevent the deterioration of articles formed from the polymer compositions which is due to microbiological attack on the polymer, the plasticizers or other polymer additives which are normally incorporated into the polymer compositions to impart desirable physical properties to the articles and to facilitate forming of the articles.
Many of the available microbiocidal materials are solid, and in order to incorporate them homogeneously into polymer compositions, it is necessary to first mix them with liquids which solubilize or disperse the microbiocidal materials uniformly and, thereafter, mix the thus-formed liquid compositions with the polymers. Unfortunately, the solubilities of many of the microbiologically active compounds in the more common solvents are quite low. Therefore, it is either difficult to incorporate a sufficiently high concentration of a microbiocidal compound with a polymer or, if a sufficiently high concentration of the microbiocidal compound can be incorporated in the polymer, an undesirably high concentration of the solvent must also be incorporated into the polymer, compromising the desirable characteristics of the polymer composition.
Attempts to solve these problems have met with varying, often limited, success. For example, U.S. Pat. No. 3,288,674 issued Nov. 29. 1966 to Yeager (reissued on Sept. 20, 1977 as Re. 29,409), U.S. Pat. No. 3,360,431 issued Dec. 26, 1967 to Yeager, and U.S. Pat. No. 3,689,449 issued Sept. 5, 1972 to Yeager and Wilson disclose the use of solvents having a labile hydrogen, such as phenols (e.g. nonyl phenol) and C.sub.5 -C.sub.12 aliphatic alcohols, to dissolve microbiocidally active phenoxarsine compounds, the resulting solutions being subsequently incorporated into polymeric resin compositions. While the C.sub.5 -C.sub.12 aliphatic alcohols were found to be useful as solvents for the phenoxarsines, their ability to aid in the incorporation of the phenoxarsines into plasticizer compositions was recognized only to a limited extent. Thus, the maximum amount of phenoxarsine disclosed as being incorporated into a plasticizer composition is only 2.5 percent by weight (based on the total weight of phenoxarsine, solvent, and plasticizer).
U.S. Pat. No. 4,663,077 issued May 5, 1987 to Rei and Wilson describes the advantageous use of aryl alkanols, such as benzyl alcohol, as solvents for microbiocidal agents which are to be formulated into solutions with carriers, such as plasticizers and/or other processing aids. The patent teaches that aryl alkanol solvents, such as benzyl alcohol, increase the levels of microbiocides, particularly phenoxarsines, which can be dissolved per amount of solvent.
U.S. Pat. No. 4,049,822 issued Sept. 20, 1977 to Rei et al. discloses that phenoxarsines can be solubilized with glycyl phosphites or glycyl phosphonates. These phosphites and phosphonates may be used in admixture with solvents having a labile hydroxyl group, such as phenols and C.sub.5 -C.sub.12 aliphatic alcohols.